When a producing horizontal wellbore formation is flowing oil, gas or water either as a single phase or any combination of phases, the flow can occur in unpredictable or suboptimal manners. For example, the rate of fluid inflow at the heel could be significantly higher than the rate at the toe. This may cause an effect know to the industry as “coning”. Coning can cause many issues including but not limited to: reduction of hydrocarbon flow, excessive water flow, excessive gas flow or excessive annular flow. Additionally, over time, the relative quantity of each phase (water, gas, crude oil) may change and one or more phases may dominate the flow. Besides the above described inflow rate variations between the heel and the toe of a well; other inflow variations between other well bore sections may exist and may also require inflow regulation.
Inflow Control Devices (ICDs) can be used to limit flow between the formation and the down hole device in which it is installed. The ICD is generally intended to regulate the flow between the formation and the production tubulars and thus may be used to mitigate coning and other inflow effects such as but not limited to gas or water breakthrough.
Prior art ICDs can be divided in two main categories:
1. Choke-type (Bernoulli principle)
2. Tortuous and helical flow path
3. Fluidics
Generally, conventional choke-type ICDs employ a circular port to create a drop in pressure. The flow path is conventionally formed in a helix about the center axis of the ICD. Choke or Nozzle type devices are normally governed by Bernoulli's principle. Although there can be some impact, the effect on pressure drop caused by variations in fluid viscosity for nozzle or choke based inflow devices is typically negligible. Conventional tortuous flow path ICDs employ a flow path formed by constraining walls in which the flow path has numerous corners along the flow axis which cause numerous directional changes in the fluid passing therethrough. Helical flow paths, guide the fluids around a circular path. Both helical and tortuous flow paths are typically governed by Darcy-Weisbach and other principles and can be sensitive to changes in fluid viscosity. Fluidic or fluid amplification devices typically take one fluid stream and jet it into another, normally from the side or other angle, causing a change in amplification or velocity or even flow direction. The flow paths in conventional ICDs are typically fixed and contain no moving parts Moreover, conventional ICD's available do not autonomously reduce water flow within in low (e.g.: <10 cP) viscosity crude.